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physics I'M STUCK PZL HELP

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A ruler stands vertically against a wall. It is given a tiny impulse at θ=0∘ such that it starts falling down under the influence of gravity. You can consider that the initial angular velocity is very small so that ω(θ=0∘)=0. The ruler has mass m= 100 g and length l= 35 cm. Use g=10 m/s2 for the gravitational acceleration, and the ruler has a uniform mass distribution. Note that there is no friction whatsoever in this problem. (See figure)

(a) What is the angular speed of the ruler ω when it is at an angle θ=30∘? (in radians/sec)

ω=

unanswered
(b) What is the force exerted by the wall on the ruler when it is at an angle θ=30∘? Express your answer as the x component Fx and the y component Fy (in Newton)

Fx=

unanswered
Fy=

unanswered
(c) At what angle θ0 will the falling ruler lose contact with the wall? (0≤θ0≤90∘; in degrees) [hint: the ruler loses contact with the wall when the force exerted by the wall on the ruler vanishes.]

θ0=

  • physics I'M STUCK PZL HELP - ,

    yes please.. that's the only question where I'm stuck too..

  • physics I'M STUCK PZL HELP - ,

    Me too!!!

  • physics I'M STUCK PZL HELP - ,

    Hi Teresa, can you do rocket problem me pls?

  • physics I'M STUCK PZL HELP - ,

    p: percentage (4.5% is burned in 155s)
    m:mass of rocket
    u:fuelspeed in meter/s!

    v=u*ln(1/(1-p))=1500*ln(1/0.955)

    a=v/t = 69.065/155= 0.4455

  • physics I'M STUCK PZL HELP - ,

    Hi Teresa, in my problem, question says The rocket burns 10 % of its mass in 290 s (assume the burn rate is constant).
    What is the speed of the rocket after a burn time of 145.0 s?

    How did you find 4.5% is burned in 155 sec? Pls.
    Thank you very much

  • physics I'M STUCK PZL HELP - ,

    because they ask you for half of the time,
    so in your case in 145 it gets burned 5% in 145 seconds

  • physics I'M STUCK PZL HELP - ,

    Thank you very much Teresa. I got green check. Now time for rular one..

  • physics I'M STUCK PZL HELP - ,

    in the equation above what is the "ln"?

  • physics I'M STUCK PZL HELP - ,

    "ln" is like log..it is in your calculator

  • physics I'M STUCK PZL HELP - ,

    is the "u" the ejected fuel in m/s instead of km/s?

  • physics I'M STUCK PZL HELP - ,

    hai Teresa can u help me for this Rocket question i don't know how to get 0.955 in the above ans !

    Consider a rocket in space that ejects burned fuel at a speed of vex= 2.0 km/s with respect to the rocket. The rocket burns 11 % of its mass in 250 s (assume the burn rate is constant).

    (a) What is the speed v of the rocket after a burn time of 125.0 s? (suppose that the rocket starts at rest; and enter your answer in m/s)

    v=

    unanswered
    (b) What is the instantaneous acceleration a of the rocket at time 125.0 s after the start of the engines?(in m/s2)

    a=

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